Temperature controlled mixing valve



y 1 c. A. BROWN 2,550,907

TEMPERATURE CONTROLLED MIXI NG VALVE Original Filed March 1, 1944[RVEHTUP CZz deA. Brown Patented May 1, 1951 TEMPERATURE CONTROLLEDMIXING VALVE Clyde A. Brown,;Luck, Wis, assignor to The Dole ValveCompany, Chicago, 111., acorporation of Illinois Original application-March 1, 1944, Serial No. 524,546. Divided; and this application.February 18, 1948, Serial No. 9,114

4 Claims. (01. 236-12) This invention relates to apparatus for producinga uniform fluid mixture from a plurality of individual fluids each ofwhich possesses certain distinct characteristics; and more particularly,to a thermostatically controlled mixer valve.

The term physical characteristic, as hereinafter employed, refers eitherto the inherent property of the fluid; or to a temporarily imposedcondition or state of. the fluid, such, for example, as temperature orpressure.

In the production of any fluid mixture having a certain predetermineddegree of uniformity from a plurality of different fluid supplies, it isnecessary to take into account certain variations which mayinadvertently occur in the fluid supplies as they are introduced intothe mixing area. Thus, for example, unless special precautions are takenin producing a mixed water supply of predetermined uniform temperature,variations in pressure and temperature of each of the individualsupplies going to make up the mixture will result in "the non-uniformityof the ultimate combination.

The present invention, therefore, contemplates means for producing auniform fluid. mixture having certain predetermined optimumcharacteristics from a plurality of individual fluid supplies havingdifferent physical characteristics or properties and for obtaining thisuniform mix-1 ture irrespective of changes in the physicalcharacteristics or properties of the component fluid supplies. 4

It is an object of the present invention to provide a novel means forproducing a uniform fluid mixture from a plurality of fluid supplieshaving diflerent physical characteristics or properties.

It is a further object of the present invention to provide novel meansfor employing one or more of the characteristics or properties of theindividual fluid supplies in controlling the admission of the properproportions of the component fluids to produce the desired fluidmixture.

Another and further object of the present invention is to provide anovel temperature controlled mixer valve.

The novel features which I believe to be characteristic of my inventionare set forth with particularity in the appended claims. My inventionitself, however, both as to its manner of construction and method ofoperation, together with further objects and advantages thereof maybest. be understood by reference to the following description taken inconnection with the accompanying drawing, in which:

Figure 1 is a longitudinal sectional view through a temperaturecontrolled mixing valve embodying the novel teachings and principles ofthe present invention; and

Figure 2 is a sectional view through the mixing valveof Figure 1 astaken along the line IIII of Figure 1. I

This application is a division of my copending application for Method ofand Means for Producing a Uniform Fluid Mixture, U. S. Serial No.524,546, filed March 1, 1944, now U. S. Patent No. 2,449,766, issuedSeptember 21, 1948, and assigned to the same assignee as the presentinvention.

As shown in Figures 1 and 2 of the drawing, the valve unit is of thesingle diaphragm pilot operated type which is advantageously employed inmixing hot and cold water to produce a mixed water supply ofpredetermined constant temperature. The valve unit comprises a casing ishaving externally threaded fluid connections H and I2, the first ofwhich is arranged to be connected to a suitable hot fluid supplyconduit, and the other is arranged to be connected to a suitable coldfluid supply conduit, The connections II and I2 have inlet passages l3and M, respectively, associated therewith which connect with a mixingchamber l5 disposed internally of the casing 10 as by means of theoutlet openings i6 and I1, respectively, taking the form of valve seats.

'An extension 18 has an outlet connection !9 which is externallythreaded for receiving a suitable conduit for handling the mixed fluiddischarged from the thermostat chamber 20 therein through, the outlet2!. The extension l8 comprises a projection 22 which extends through thewall of the casing I!) in such fashion that the flangedportion 2-3 ofthe extension 18 may be secured to said casing, as, for example, byscrews 24. A suitable gasket may advantageously be provided to preventleakage between the casing 10 and the extension 18.

The thermostat chamber 20 in the extension [8 communicates with themixing chamber I5 in the casing It as by means of an opening 25. Theopening 25 which extends through the end wall of the projection 22 has aplate 26 mounted therein having a centrally disposed orifice 21. Theplate 26 may be secured in the end of the projection 22 of extension I8as by being press flt against a shoulder 28 formed about the opening 25in the end of said projection 22.

The valve for controlling the flow of fluid through each pair of outletopenings 16 and i1 in the inlet passages l3 and 14, respectively,advantageously takes the form of a spool valve 29. The valve 29 has aplurality of spaced, generally frusto-conically shaped portions 39 and3| thereon for seating in said outlet openings l6 and H. The valve 29 issupported at one end thereof by means of a coil spring 32 which isadapted to be adjustably positioned against the end of said valve as bymeans of the guide member 33 adjustably threaded into the wall of casing[0.

The valve 29 has a threaded rod 34 extending substantially axially fromits other end through an opening 35 in the wall of the casing ID toengage a diaphragm 35. The rod 34 extends through a centrally disposedaperture in the diaphragm 36 and is secured thereto by a nut 31 threadedon rod 34 and backed by a washer 38. The diaphragm 35 has an annularbead 39, an imperforate web portion 45, and a reinforced centrallydisposed portion M.

A bore 42 is provided in the wall of the casing I and disposedconcentrically with the opening 35 to receive diaphragm 33 which is heldin place in the base thereof by the thimble 43 which is threaded intothe bore 42 and engages the bead 39 of said diaphragm. The joint formedbetween the thimble 43 and the outer wall of the casing It! mayconveniently be sealed by the use of suitable gaskets.

The thimble 43 is provided with a recess 44 in the underside thereofdisposed adjacent the diaphragm 35. The recess 44 is adapted tocommunicate with an annular groove 45 formed about the externalperiphery of the thimble 43 adjacent the end thereof contacting the beadportion 39 of the diaphragm 36 through a plurality of ports 46 extendingsubstantially radially through the wall of said thimble 43.

The annular groove 45 on the thimble 43 advantageously forms acompletely closed channel with respect to the wall of the bore 42 in thecasing l0 and is connected, as by means of a passageway 41, with theinlet passage [3 associated with the hot fluid connection H. A similarpassageway 48 connects the aforementioned channel formed between theannular groove 45 and the wall of the bore 42 with the externalperiphery of the projection 22 of the extension l8.

A guide member 49 which may advantageously be of generally cylindricalform is inserted in and extends through the wall of the projection 22 ofthe extension IS. The guide member 49 is so disposed that an axiallyextending passage 50 in said guide member 49 connects the base of a bore51 therein with the passageway 48 formed in the casing l and connectingwith the groove 45. The bore 5| in the inserted guide member 49 isprovided in its base with a substantially flexible washer element 52,the central aperture of which registers with the passage 50 and isadapted to receive for controlling the flow of fluid therethrough thesubstantially conically shaped end of a pilot valve 53 which extendsinto the bore 5!.

The pilot valve 53 is secured to the free end of a thermo-sensitivemeans in the form of a bimetal coil type thermostatic element 54. Theother end of thermostatic element 54 is secured to a pin 55 which isdisposed within and extends transversely of the thermostat chamber 2! inthe extension IS.

The operation of the above described thermostatically controlled mixervalve will now" be referred to.

For the purpose of illustration, let us assume that the temperature ofthe fluid mixture rises above that for which the thermostatic element 54is adjusted. In such case, the thermostatic element 54 causes the pilotvalve 53 to approach a seating position against the washer 52, as shownin Figure 1, thereby temporarily closing ofi the passageway 48 andpassage 50 to cause the fluid pressure within the recess 44 to increase.This increased pressure on the diaphragm 35 causes the valve 29 to moveaxially against the spring 32 thereby tending to seat the frusto-conicalportions 30 in the outlets I6 reducing the flow of hot fluid admitted tomixing chamber 15 from inlet passage l3. The frusto-conical portions 3|are simultaneously caused to move away from a seating position in'outlets ll thereby increasing the flow of cold fluid to the mixingchamber [5.

As soon as the temperature of the mixed fluid is adjusted to thepredetermined temperature setting for the thermostatic element 54, thepilot valve 53 is immediately shifted to open the passageway 48 andpassage 55. This operation reduces the fluid pressure in recess 44 andpermits the spring 32 to overcome the pressure against diaphragm 35,thereby shifting valve member 29 to reduce the flow of cold fluid andincrease the flow of hot fluid into the mixing chamber 15.

The opposite operation takes place if the temperature of the mixed fluiddrops. The mixer valve unit of Figure l is sensitive to pressurevariations occurring in the individual fluid supplies.

The principle of operation involved, therefore, is one of utilizing thepressure in one of the individual fluid supplies controlled by a pilotvalve actuated by a thermo-sensitive element to create a pressuredifferential to open and close the outlets through which the fluidsupplies are admitted to the mixing area.

While I have shown-a particular embodiment of my invention, it will, ofcourse, be understood that I do not Wish to be limited thereto sincemany modifications may be made, and I, there: fore, contemplate by theappended claims to cover all such modifications as fall within the truespirit and scope of my invention.

I claim as my invention:

1. A mixer valve comprising a housing, an inlet in said housing for eachof two fluids under pressure, valve means in each of said inlets, anoutlet in said housing for the mixed fluid, a mixing chamber in saidhousing, an auxiliary fluid chamber within said housing in constant andunvarying fluid communication with only one of said inlets, a flexiblemembrane separating said auxiliary chamber from said mixing chamber anddirectly exposed to the fluid pressure of both chambers, a fluid drainfor said auxiliary chamber, a pilot valve in said drain, said pilotvalve being mounted to selectively open and close said drain, springmeans positioned to supplement the force exerted on said membrane by thefluid pressure in said mixing chamber and thereby balance the forceexerted on said membrane by the fluid pressure of said auxiliarychamber, said valve means being operatively connected to said membraneto be moved thereby to simultaneously open one inlet and close the otherin varying degree to control the admission of fluid to the mixingchamber.

2. A mixer valve comprising a housing, an inlet in said housing for eachof two fluids under pressure, valve means in each of said inletsmechanically connected together to operate as a single unit, an outletin said housing for the mixed fluid, a mixing chamber in said housingbetween said inlets and said outlet, an auxiliary fluid chamber withinsaid housing in constant and unvarying fluid communication with one ofsaid inlets, a flexible membrane separating said auxiliary chamber fromsaid mixing chamber and directly exposed to the fluid pressure of bothchambers, said valve means being mechanically connected to saidmembrane, biasing means normally urging said valve means to a positionwhich tends to reduce the size of said auxiliary chamber, a fluid drainfor said auxiliary chamber, said biasing means being balanced againstthe differential force acting on said membrane, a pilot valve in saiddrain, said pilot valve being mounted to selectively open and close saiddrain thereby to simultaneously open one inlet and close the other invarying degree to control the admission of fluid to the mixing chamber.

3. A mixer valve comprising a housing, an inlet in said housing for eachof two fluids under pressure, valve means in each of said inletsmechanically connected together to operate as a single unit, an outletin said housing for the mixed fluid, a mixing chamber in said housingbetween said inlets and said outlet, an auxiliary fluid chamber withinsaid housing in constant and unvarying fluid communication with one ofsaid inlets, a flexible membrane separating said auxiliary chamber fromsaid mixing chamber, and directly exposed to the fluid pressure of bothchambers, said valve means being mechanically connected to saidmembrane, biasing means normally urging said valve means to a positionwhich tends to reduce the size of said auxiliary chamber, said biasingmeans being balanced against the differential force acting on saidmembrane, a fluid drain for said auxiliary chamber, a pilot valve insaid drain, thermal responsive means mounted in said mixing chamber andconnected to said pilot valve to selectively open and close said drainin response to variations in the temperature of the mixed fluid.

4. A mixer valve comprising a housing, an in et in said housin fo eachof two fluids u der pressure, a unitary valve member having valveportions in each of said inlets and mounted so that when one valveportion is closing its associated inlet another valve portion is openingits associated inlet, an outlet in said housing for the mixed fluid, amixing chamber in said housing between said inlets and said outlet, anauxiliary fluid chamber within said housing opposite one end of saidunitary valve member, a compression spring mounted in said housingopposite the other end of said unitary valve member and bearingthereagainst to urge said unitary valve member toward said auxiliarychamber, a flexible membrane separating said auxiliary chamber from saidmixing chamber, a portion of said membrane being secured to said one endof said unitary valve member, an open fluid passageway between one ofsaid inlets and said auxiliary chamber, a second fluid passagewaybetween said auxiliary chamber and said mixing chamber, a pilot valve insaid second fluid passageway, and a temperature responsive elementdisposed in said mixing chamber and connected to said pilot valve toselectively move said pilot valve to open and closed positions when thetemperature of the mixed fluid varies from a predetermined desiredtemperature.

CLYDE A. BROWN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,869,663 Cartier Aug. 2, 19322,217,017 Hooper Oct. 8, 1940 2,272,403 Fields Feb. 10, 1942 2,308,165Fields Jan. 12, 1943 2,310,975 Lund Feb. 16, 1943 2,415,994 Curtis Feb.18, 1947 FOREIGN PATENTS Number Country Date 720,112 France Dec. 3, 1931

